Sulfide herbicide antidote compositions and method of use

ABSTRACT

Herbicidal compositions comprising an active herbicidal compound and an antidote therefor and the methods of use of the herbicide compositions are described herein; the antidote compound corresponds to substituted sulfides having the formula 
     
         R.sub.1 --S--R.sub.2 
    
     wherein R 1  is selected from the group consisting of di-p-chlorophenylmethyl, phthalimidomethyl, pentachlorophenyl, alkenyl, haloalkyl, chloroalkenyl, aminoalkyl, hydroxyethyl, carboxymethyl, N-alkylcarbamoylmethyl, mono-chlorobenzamidoethyl, dichlorobenzamidoethyl, mono-bromobenzamidoethyl, β-S-ethylthiocarboxylaminoethyl and dichloroacetamidoethyl; and R 2  is selected from the group consisting of p-chlorophenyl, alkyl, haloalkyl, α-hydroxytrichloroethyl, alkenyl, chloroalkenyl, aminoalkyl, cyanoalkyl, cyanochloroalkyl, mono-chlorobenzyamidoethyl, dichlorobenzamidoethyl, mono-bromobenzamidoethyl, β-S-ethylthiocarboxylaminoethyl and dichloroacetamidoethyl.

This is a division, of application Ser. No. 394,230 filed Sept. 4, 1973now abandoned.

BACKGROUND OF THE INVENTION

Among the many herbicidal compounds commercially available, thethiocarbamates alone or admixed with other herbicides, such as thetriazines, have reached a relatively high degree of commercial success.These herbicides are immediately toxic to a large number of weed pestsat different concentrations varying with the resistance of the weedpests. Some examples of these compounds are described and claimed in theU.S. Pat. Nos. 2,913,327, 3,037,853, 3,175,897, 3,185,720, 3,198,786 and3,582,314. It has been found in practice that the use of thesethiocarbamates as herbicides on crops sometimes causes serious injuriesto the crop plant. When used in the recommended amounts in the soil tocontrol many broadleaf weeds and grasses, serious malformation andstunting of the crop plants result. This abnormal growth in the cropplants results in loss of crop yield. Previous attempts to overcome thisproblem involves the treatment of the crop seed with certainantagonistic agents prior to planting, see U.S. Pat. Nos. 3,131,509 and3,564,768. These antagonistic agents have not been notably successful.The aforementioned patent specifically exemplifies the treatment ofseeds employing compounds of a different chemical class not suggestiveof the present invention.

DESCRIPTION OF THE INVENTION

It has been discovered that plants can be protected against injury byvarious herbicides of the thiocarbamate-type or substitutedacetanilide-type, alone or mixed with other compounds and/or thetolerance of the plants can be substantially increased to the activecompounds of the above-noted U.S. Patents by adding to the soil anantidote compound corresponding to the following formula:

    R.sub.1 --S--R.sub.2

wherein R₁ is selected from the group consisting ofdi-p-chlorophenylmethyl, phthalimidomethyl, pentachlorophenyl, alkenyl,chloroalkenyl, aminoalkyl, hydroxyethyl, carboxymethyl,N-alkylcarbamoylmethyl, haloalkyl, mono-chlorobenzamidoethyl,dichlorobenzamidoethyl, mono-bromobenzamidoethyl,β-S-ethylthiocarboxylaminoethyl and dichloroacetamidoethyl; and R₂ isselected from the group consisting of p-chlorophenyl, alkyl, haloalkyl,α-hydroxytrichloroethyl, alkenyl, chloroalkenyl, aminoalkyl, cyanoalkyl,cyanochloroalkyl, mono-chlorobenzylamidoethyl, dichlorobenzamidoethyl,mono-bromobenzamidoethyl, β -S-ethylthiocarboxylaminoethyl anddichloroacetamidoethyl.

In the above description, the following embodiments are intended for thevarious substituent groups: For R₁, alkenyl preferably includes thosemembers containing at least one olefinic double bond and from 3 to 6carbon atoms, inclusive, in both branched and straight chainconfigurations; chloroalkenyl includes mono-, di-, tri- and tetra-chlorosubstitution in alkenyl moieties having 3 to 6 carbon atoms, inclusive;the term aminoalkyl includes those members having at least one aminogroup (NH₂ --) and an alkyl moiety having from 1 to 6 carbon atoms,inclusive. For R₂, alkyl preferably includes those members having from 1to 8 carbon atoms, inclusive, in both branched and straight chainconfigurations; alkenyl preferably includes those members containing atleast one olefinic double bond and from 3 to 6 carbon atoms, inclusive,in both branched and straight chain configurations; chloroalkenylincludes mono-, di-, tri- and tetra-chloro substitution in alkenylmoieties having 3 to 6 carbon atoms, inclusive; aminoalkyl includesthose members having at least one amino group (NH₂ --) and an alkylmoiety having from 1 to 6 carbon atoms, inclusive; cyanoalkyl includesthose members having at least one cyano group (--CN) and an alkyl moietyhaving from 1 to 4 carbon atoms; cyanochloroalkyl includes those membershaving at least one cyano group, from 1 to 4 chlorine atoms, inclusive,and an alkyl moiety having from 2 to 6 carbon atoms, inclusive. The termhaloalkyl preferably includes those alkyl members substituted with atleast one halogen, selected from chlorine and bromine and having from 1to 4 carbon atoms.

As an alternative mode of action, the compounds of this invention mayinterfere with the normal herbicidal action of the thiocarbamate-typeand other herbicides to render them selective in their action. Whichevermode of action is present, the corresponding beneficial and desirableeffect is the continued herbicidal effect of the thiocarbamate or otherherbicide with the accompanying decreased herbicidal effect on desiredcrop species. This advantage and utility will become more apparenthereinafter.

Therefore, the terms herbicide, antidote or antidotal amount, is meantto describe that effect which tends to counteract the normal injuriousherbicidal response that the herbicide might otherwise produce. Whetherit is to be termed a remedy, interferant, protectant, safening agent, orthe like, will depend upon the exact mode of action. The mode of actionis varied, but the effect, which is desirable, is the result of themethod of treating the soil in which a crop is planted. Hitherto, therehave been no systems which have been satisfactory for this purpose.

The compounds of this invention represented by the above formula can beprepared by several different procedures depending upon the startingmaterials.

GENERAL PROCEDURE FOR PREPARATION OF ALLYL AND BENZYL SULFIDES

The active halide (allyl or benzyl type) is dissolved in isopropylalcohol or other suitable solvent, and sodium sulfide nona-hydrate whichhad been coarsely ground was added. The addition is at reducedtemperature, approximately 15° C. At the end of the reaction, theprecipitated sodium chloride is removed by filtration and the solventremoved in vacuo. The residue is taken up in benzene and ether andwashed with three portions of water. The solution is dried and thesolvent distilled in vacuo.

GENERAL PROCEDURE FOR PREPARATION OF MIXED SULFIDES

An organo mercaptan is dissolved in a suitable solvent, such as dioxane,isopropyl alcohol or the like. Sodium hydroxide solution is added andthe reaction mixture heated. An active organo halide is added and themixture refluxed. Work-up is by normal procedures of extraction, solventremoval, distillation or crystallization.

The compounds and the present invention and their preparation are moreparticularly illustrated by the following examples. Following theexamples of preparation is a table of compounds which may be preparedaccording to the procedures described herein. Compound numbers have beenassigned to them and are used for identification through the balance ofthe specification.

EXAMPLE I PREPARATION OF BIS-(3,3-DICHLOROALLYL)-SULFIDE

1,1,3-trichloropropene-1 (1100 g., 7.5 M) was dissolved in one liter ofisopropanol and sodium sulfide nona-hydrate (900 g., 3.75 M) which hadbeen coarsely powdered, was added at one time at 15° C. The mixture wasstirred at 25°-30° C. for 3 hours and at 50° C. for 2 hours. It wasallowed to stand overnight at room temperature. The precipitated sodiumchloride was filtered off and the solvent removed in vacuo. The residualoil was taken up in a mixture of one liter of benzene and one liter ofether and washed with three 400 ml. portions of water. The solution wasdried over magnesium sulfate and the solvent removed in vacuo. Theresidual solvent was removed at about 0.5 mm. There was obtained a redbrown liquid, yield: 853 g. (90%). Structure was confirmed by NMRspectroscopy. The product distilled at b.p. 75°-77°/35 mm.

EXAMPLE II PREPARATION OF BIS-(β-M-CHLOROBENZAMIDOETHYL)SULFIDE.

To a solution of bis-(β-aminoethyl)sulfide (2.5 g., 0.021 M) and sodiumhydroxide (1.6 g., 0.04 M) in 20 ml. of water and 40 ml. of ether wasadded a solution of m-chlorobenzoyl chloride (7.0 g., 0.04 M) in 15 ml.of ether at 10°-20° C. A precipitate appeared. The mixture was stirred45 minutes at room temperature and the solid filtered, washed with waterand dried. The product was a white solid. m.p. 150°-152° C. Itsstructure was confirmed by IR spectroscopy. Yield: 7.0 g. (88%).

                                      TABLE I                                     __________________________________________________________________________    R.sub.1SR.sub.2                                                               COMPOUND                        m.p. ° C.                              NUMBER  R.sub.1     R.sub.2     or N.sub.D.sup.30                             __________________________________________________________________________    1     (Cl-phenyl).sub.2 CH                                                                       p-Cl-phenyl  1.6460                                               ##STR1##    CH(CH.sub.3).sub.2                                                                         57-62                                         3                                                                                    ##STR2##    p-Cl-phenyl  107-112                                       4                                                                                    ##STR3##    CH.sub.2 CH.sub.3                                                                          64-72                                         5                                                                                    ##STR4##    CH.sub.2 CH.sub.2 CH.sub.3                                                                 1.5561                                        6                                                                                    ##STR5##    CH.sub.2 CH.sub.2 Cl                                                                       133-134                                       7     p-Cl-phenyl                                                                                 ##STR6##    73-76                                         8     CCl.sub.2CHCH.sub.2                                                                        CCl.sub.2CHCH.sub.2                                                                        75-77/35mm.                                    9     phenyl                                                                                     ##STR7##     1.6073                                       10    CCl.sub.2CClCH.sub.2                                                                       CH.sub.2 CH.sub.3                                                                          1.5325                                        11    CH.sub.3 CClCHCH.sub.2                                                                     CH.sub.3 CClCHCH.sub.2                                                                     1.5387                                         12                                                                                  ##STR8##                                                                                   ##STR9##     1.5217                                       13    CHClCHCH.sub.2                                                                             CHClCHCH.sub.2                                                                             1.5270                                        14    CH.sub.2 CHCH.sub.2                                                                        CH.sub.2CHCH.sub.2                                                                         1.4850                                        15    HOCH.sub.2 CH.sub.2                                                                        CH.sub.3 CH.sub.2                                                                          1.4816                                        16    CCl.sub.2CClCH.sub.2                                                                       CCl.sub.2CClCH.sub.2                                                                       1.5810                                        17    phenyl       CH.sub.2 CHCCl.sub.2                                                                       1.5905                                        18    ClCH.sub.2 CH.sub.2 CH.sub.2                                                               CH.sub.2 CH.sub.2 CH.sub.2 Cl                                                              1.4528                                        19    HOCH.sub.2 CH.sub.2                                                                        n-C.sub. 8 H.sub.17                                                                        1.4710                                        20    H.sub.2 NCH.sub.2 CH.sub.2                                                                 CH.sub.2 CH.sub.2 NH.sub.2                                                                 b.p. 64-67° C.                                                         .3-.4mm                                       21                                                                                   ##STR10##                                                                                  ##STR11##   130-132                                       22                                                                                   ##STR12##                                                                                  ##STR13##   148-151                                       23                                                                                   ##STR14##                                                                                  ##STR15##   150-152                                       24                                                                                   ##STR16##                                                                                  ##STR17##   170-172                                       25    ClCHCClCH.sub.2                                                                            CH.sub.2 CClCHCl                                                                           red/brown                                                                     liquid                                        26                                                                                   ##STR18##                                                                                  ##STR19##   111-115                                       __________________________________________________________________________

The compounds of this invention were employed in effective herbicidalantidote compositions comprising thiocarbamates or substitutedacetanilides in combination with antidote compounds describedhereinabove. They were tested in the following manner.

CORN SEED TREATMENT TEST

Small flats were filled with Felton loamy sand soil. Soil incorporatedherbicides were applied at this time. The soil from each flat was placedinto a five-gallon cement mixer where the soil was mixed as theherbicides were applied using a predetermined amount of a stock solutioncontaining 936 mg. of 75.5% active ingredient to 100 ml. of water. Oneml. of stock solution was applied to the soil in a volumetric pipet foreach pound of herbicide desired. One ml. of stock solution contained 7mg. of herbicide which equals one pound per acre when applied to thesoil in the flats. After the herbicide incorporation, the soil wasplaced back into the flats.

Flats of herbicide-treated and untreated soil were then ready to beplanted. A pint sample of soil was removed from each flat and placednext to each flat for later use in covering up the seeds. The soil wasleveled and rows one-half inch deep were made for planting seeds.Alternating rows of treated and untreated crop seeds were sown. In eachtest, six DeKalb XL 374 field corn seeds were planted in each row. Rowswere approximately 11/2 inches apart in the flat. Seeds were treated byplacing 50 mg. of the antidote compound with 10 grams of corn seed in asuitable container and shaking them until the seeds were uniformlycovered with the compound. Antidote compounds were also applied asliquid slurries and powders or dusts. In some cases, acetone was used todissolve powdered or solid compounds so they could be more effectivelyapplied to the seeds.

After the flats were seeded, they were covered with the one pint of soilwhich had been removed just prior to planting. Flats were placed ongreenhouse benches where temperatures ranged from 70°-90° F. Flats werewatered by sprinkling as needed to assure good plant growth. Per centcontrol ratings were taken two to three weeks after the treatments wereapplied.

In each test, the herbicide was applied alone, in combination with theseed protectant, and the seed protectant was applied alone to check forphytotoxicity. The untreated adjacent row was employed to observe anybeneficial lateral movement of the antidote compound through the soil.The degree of the effect was noted by comparison with the control. Theresults of these tests are tabulated in Table II.

                  TABLE II                                                        ______________________________________                                        Per Cent Injury to Corn from EPTC*                                            Seed Treatment Test                                                                       Per Cent Injury, weeks                                                              Treated     Untreated                                                         Seed        Seed                                            COMPOUND EPTC     (0.5% w/w)  Adjacent Row                                    NUMBER   lb/A     (2 wks)     (3 wks)                                         ______________________________________                                        1        6        50          50                                              2        6        40          65                                              3        6        50          80                                              4        6        65          70                                              5        6        80          70                                              EPTC                                                                          Untreated                                                                     Seed     --       90          --                                              ______________________________________                                         *=S-ethyl dipropylthiocarbamate                                          

PROCEDURE: MULTICROP ANTIDOTE SCREEN

Flats were filled with Felton loamy sand soil. A variety of grass andbroadleaf crops were used in these tests. EPTAM® (EPTC) was incorporatedat 1/2, 3 or 5 lb/A, while a constant rate of 5 lb/A of the additive wasused. LASSO® (EPTC) or ORDRAM® (S-ethylhexahydro-1-H-azepine-1-carbothioate) and the candidate herbicideantidote were applied separately by pipetting measured amounts of theappropriate stock solutions into the soil during incorporation in a 5gallon rotary cement mixer. Stock solutions were prepared as follows:

A. 1/2 lb/A: 670 mg. of EPTC 6E (75.5% a.i.) is diluted with 500 ml. ofdeionized water so that 2 ml. equals 1/2 lb/A flat.

B. 5 lb/A: 6700 mg. of EPTC 6E (75.5% a.i.) is diluted with 500 ml. ofdeionized water so that 2 ml. equals 5 lb/A flat.

C. 2 lb/A: 427 mg. LASSO 4E is diluted with 100 ml. of deionized waterso that 1 ml. equals 2.05 mg. (a.i.) and 4 ml. equals 8.2 mg. equivalentto 2 lb/A flat.

D. 6 lb/A: 4312 mg. of ORDRAM 6E (71.3% a.i.) was diluted with 500 ml.of deionized water so that 4 ml. of the stock solution equaled 6 lb/Awhen applied to a flat.

Antidote stock solutions are prepared by diluting 102 mg. of technicalmaterial with 10 ml. of acetone 1% Tween 20® (polyoxyethylene sorbitanmonolaurate) so that 2 ml. equals 5 lb/A flat.

After the soil is treated with both herbicide and additive, the soil istransferred from the mixer back into the flat where it is then preparedfor seeding. The initial step in preparation is to remove a one pintsample of soil from each flat to be retained and used to cover the seedsafter planting. The soil is then leveled and rows one-quarter inch deepare made in each flat. Flats treated with the herbicide and additive areseeded with corn (Zea maize), sugarbeets (Beta vulgare), sunflower(Helianthus annus), cotton (Gossypium hirsutum), soybeans (Glycine max)and oilseed rape (Brassica napus). Flats treated with 1/2 lb/A of EPTAMare seeded with red oats (Avena byxantina), milo (Sorghum vulgare),wheat (Triticum aestivum), giant foxtail (Seteria feberii), rice (Oryzasativa) and barley (Hordeum vulgare). Flats treated with 2 lb/A of LASSOare seeded with corn (Zea maize), wheat (Triticum aestivum), rice (Oryzasativa), milo (Sorghum vulgare), and barley (Hordeum vulgare). Seeds arethen covered with the pint soil sample removed prior to seeding.

The flats are then placed on greenhouse benches where temperatures aremaintained between 70°-90° F. The soil is watered by sprinkling toassure good plant growth.

Injury ratings are taken at 2,3 or 4 weeks after the treatments areapplied. Soil treated with the herbicides alone at 1/2, 2, 3, 5 or 6lb/A is included to provide a basis for determining the amount of injuryreduction provided by the herbicide antidotes. The percent protection isdetermined by a comparison with flats not treated with the candidateantidote, but with the herbicide alone. Results are given in Table III.

                  TABLE III                                                       ______________________________________                                        MULTICROP SCREEN RESULTS                                                      PER CENT PROTECTION                                                           ______________________________________                                        COM-             Rate of   Rate of      % Pro-                                POUND            Herbicide                                                                              Antidote      tection                               No.              lb/A     lb/A   Crop   (4 wks)                               ______________________________________                                         6     EPTC.sup.a                                                                              3.0      5.0    corn   100                                          EPTC      3.0      5.0    soybeans                                                                             40                                    7      EPTC      3.0      5.0    corn   75                                     8     EPTC      0.5      5.0    sorghum                                                                              100                                          EPTC      0.5      5.0    rice   30                                           EPTC      3.0      5.0    corn   100                                          ORDRAM.sup.b                                                                            6.0      5.0    rice   72                                           LASSO.sup.c                                                                             2.0      5.0    wheat  38                                           LASSO     2.0      5.0    sorghum                                                                              100                                    9     EPTC      0.5      5.0    sorghum                                                                              50                                           EPTC      0.5      5.0    rice   44                                    10     EPTC      3.0      5.0    mustard                                                                              100                                   11     EPTC      0.5      5.0    sorghum                                                                              50                                           EPTC      0.5      5.0    rice   38                                           EPTC      3.0      5.0    corn   67                                    12     EPTC      3.0      5.0    corn   100                                   13     EPTC      5.0      5.0    sunflower                                                                            67 (3)                                14     EPTC      0.5      5.0    rice   100 (3)                                      ORDRAM    6.0      5.0    rice   30                                    15     EPTC      0.5      5.0    rice   100 (3)                               16     EPTC      0.5      1.0    rice   11                                    17     EPTC      0.5      5.0    sorghum                                                                              67                                           EPTC      3.0      5.0    corn   83                                    18     EPTC      0.5      5.0    barley 45                                    19     EPTC      5.0      5.0    sunflower                                                                            67                                    20     EPTC      5.0      5.0    rape   87                                    21     EPTC      0.5      5.0    rice   86                                    22     EPTC      0.5      5.0    rice   100                                          EPTC      5.0      5.0    sunflower                                                                            75                                    23     EPTC      0.5      5.0    rice   100                                          EPTC      5.0      5.0    sunflower                                                                            75                                    24     EPTC      0.5      5.0    rice   62                                    25     EPTC      5.0      5.0    corn   15                                    26     EPTC      5.0      5.0    corn   45                                    ______________________________________                                         .sup.a = S-ethyl dipropylthiocarbamate                                        .sup.b = S-ethyl hexahydro-1H-azepine-1-carbothioate                          .sup.c = 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide             

The antidote compounds and compositions of the present invention can beused in any convenient form. Thus, the antidote compounds can beformulated into emulsifiable liquids, emulsifiable concentrates, liquid,wettable powder, powders, granular or any other convenient form. In itspreferred form, a non-phytotoxic quantity of an herbicidal antidotecompound is admixed with a selected herbicide and incorporated into thesoil prior to or after planting the seed. It is to be understood,however, that the herbicides can be incorporated into the soil andthereafter the antidode compound can be incorporated into the soil.Moreover, the crop seed itself can be treated with a non-phytotoxicquantity of the compound and planted into the soil which has beentreated with herbicides, or untreated with the herbicide andsubsequently treated with the herbicide. The addition of the antidotecompound does not affect the herbicidal activity of the herbicides.

The amount of antidote compound present can range between about 0.01 toabout 15 parts by weight of antidote compound described herein per eachpart by weight of herbicide. The exact amount of antidote compound willusually be determined on economic ratios for the most effective amountusable. It is understood that a non-phytotoxic quantity of antidotecompound will be employed in the herbicidal compositions describedherein.

The herbicides indicated in the tables and elsewhere are used at rangewhich produce effective control of undesirable vegetation. The rates arewithin the recommended amounts set forth by the supplier. Therefore, theweed control in each instance is commercially acceptable within thedesired or recommended amount.

It is clear that the classes of herbicidal agents described andillustrated herein are characterized as effective herbicides exhibitingsuch activity. The degree of this herbicidal activity varies amongspecific compounds and among combinations of specific compounds withinthe classes. Similarly, the degree of activity to some extent variesamong the species of plants to which a specific herbicidal compound orcombination may be applied. Thus, selection of a specific herbicidalcompound or combination to control undesirable plant species readily maybe made. Within the present invention are prevention of injury to adesired crop species in the presence of a specific compound orcombination may be achieved. The beneficial plant species which can beprotected by this method is not intended to be limited by the specificcrops employed in the examples.

The herbicidal compounds employed in the utility of this invention areactive herbicides of a general type. That is, the members of the classare herbicidally effective against a wide range of plant species with nodiscrimination between desirable and undesirable species. The method ofcontrolling vegetation comprises applying an herbicidally effectiveamount of the hereindescribed herbicidal compounds to the area or plantlocus where control is desired. The compositions as set forth in thisinvention include those wherein the preferred active herbicidal compoundis selected from EPTC, S-ethyl diisobutyl thiocarbamate, S-propyldipropyl thiocarbamate, S-2,3,3-trichloroallyl-diisopropylthiocarbamate, S-ethyl cyclohexyl ethyl thiocarbamate,2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide, S-ethylhexahydro-1H-azepine-1-carbothioate, 2-chloro-N-isopropylacetanilide,N,N-diallyl-2-chloroacetamide, S-4-chlorobenzyl diethyl thiocarbamate,2-chloro-4-ethylamino-6-isopropylamino-s-triazine,2-chloro-4,6-bis(ethylamino)-s-triazine,2(4-chloro-6-ethylamine-s-triazine-2-yl-amino)-2-methylpropionitrile,2-chloro-4-cyclopropylamino-6-isopropylamino-s-triazine,2,4-dichlorophenoxyacetic acid, its esters and salts, and3-(3,4-dichlorophenyl)-1,1-dimethylurea and combinations thereof.

An herbicide as used herein means a compound which controls or modifiesthe growth of vegetation or plants. Such controlling or modifyingeffects include all deviations from natural development; for example,killing, retardation, defoliation, desiccation, regulation, stunting,tillering, stimulation, dwarfing and the like. By "plants", it is meantgerminant seeds, emerging seedlings, and established vegetation,including the roots and above-ground portions.

What is claimed is:
 1. The method of protecting a crop from injury dueto a thiocarbamate herbicide, comprising applying to the habitat priorto planting from about 0.01 to about 15 parts by weight for each part byweight of the thiocarbamate herbicide an antidote compound correspondingto the formula

    R.sub.1 --S--R.sub.2

wherein R₁ is selected from the group consisting of phthalimidomethyl;and R₂ is selected from the group consisting of alkyl, having from 1 to8 carbon atoms, inclusive.
 2. The method according to claim 1 in whichR₂ is isopropyl.
 3. The method according to claim 1 in which R₂ isethyl.
 4. The method according to claim 1 in which R₂ is n-propyl.